Eu2O3–Cu/NC nanocomposite catalyst with improved oxygen reduction reaction activity for Zn-air batteries

Abstract

Rare earth oxide promoted transition metal composite catalyst Eu2O3–Cu/NC with outstanding oxygen reduction reaction (ORR) performance, is constructed by hydrothermal and subsequent high-temperature calcination, considering replacing Pt/C. This synthesis method yields Eu2O3–Cu nanoparticles with uniform distribution, improved oxygen vacancies and increased content of N-doping. And the strong synergistic effect was created between promoter Eu2O3 and chief Cu. In addition, the accommodate adsorption and transfer of O species endow Eu2O3–Cu/NC the improved ORR activity than Eu2O3/NC and Cu/NC. Meanwhile, the stability of Eu2O3–Cu/NC is also strengthened compared to Cu/NC on account of the interaction of active sites, and the H2O2 yield of Eu2O3–Cu/NC is very low. For practical application, a rechargeable Zn-air battery with an air cathode of Eu2O3–Cu/NC displays a larger power density, excellent charge-discharge cycle stability and good rate capability. The designed composite shows potential application prospects in the fields of energy conversion.